The invention is directed in general to vehicle brake systems. In particular the invention relates to a hydraulic vehicle brake having a hydraulic chamber and having a brake piston that delimits the hydraulic chamber.
From DE 197 32 168 A, and corresponding U.S. Pat. No. 6,394,235 B1, both of which are incorporated by reference herein in their entirety, a hydraulic vehicle brake is known, in which a friction lining by means of a brake piston may be pressed by hydraulic pressure against a brake disk in order to slow down the rotation thereof during a service braking operation. For this purpose, in a conventional manner hydraulic fluid is introduced under pressure into a hydraulic chamber, one boundary wall of which is formed by the brake piston. The pressure in the hydraulic chamber leads to a displacement of the brake piston and hence of the friction lining in the direction of the brake disk. As soon as the friction lining moves into abutment with the rotating brake disk, the vehicle is slowed down.
To allow the vehicle brake to be used not only as a service brake but also as a locking brake—also known as a parking brake, it comprises a locking device for mechanically locking the brake piston in a state, in which the friction lining is in engagement with the brake disk. In the vehicle brake known from DE 197 32 168 A, the locking device takes the form of a nut/spindle arrangement.